Field of the Invention
The present invention relates to a pneumatic tire having a carcass ply which is wound up to an outer side from an inner side around a bead core, and a chafer which is wound up to the inner side from the outer side around the bead core and is arranged so as to wrap the carcass ply.
Description of the Related Art
Conventionally, in a pneumatic tire which is particularly used in a heavy vehicle such as an industrial vehicle and a construction vehicle, there has been a risk that a trouble such as separation occurs beginning at a wound-up end of the carcass ply which is wound up around the bead core. As a result, a reinforcing member called as a chafer has been generally arranged along the carcass ply, as disclosed in the following Patent Documents 1 to 3. However, even in the case that the chafer is arranged, durability may be deteriorated due to a protruding deformation of a bead portion, and there has been room for further improvement.
FIG. 3 is a diagram illustrating a protruding deformation of a bead portion. In a tire at the time of traveling, a side wall portion greatly bends by application of an internal pressure and a load, and a bead portion 1 deforms while protruding outward along a rim flange 91 as shown in the drawing. In the case that such a protruding deformation is repeated according to rolling of the tire, an inner liner rubber 5 constructing a tire inner surface is elongated, a great strain acts on a wound-up end 62E in a tire inner surface side of a chafer 6, and a crack tends to be generated beginning at the strain.